The main function of a fuse is to_____________?
A. protect the line
B. open the circuit
C. protect the appliance
D. prevent excessive currents
The direction of magnetic lines of force is________________?
A. From south pole to north pole
B. From north pole to south pole
C. From one end of the magnet to another
D. None of the above
A permeable substance is one_____________?
A. Which is a good conductor
B. Which is a bad conductor
C. Which is a strong magnet
D. Through which the magnetic lines of force can pass very easily
A magnetic field exists around____________?
A. Iron
B. Copper
C. Aluminium
D. Moving charges
The materials having low retentivity are suitable for making_____________?
A. Weak magnets
B. Temporary magnets
C. Permanent magnets
D. None of the above
Tesla is a unit of_____________?
A. Field strength
B. Inductance
C. Flux density
D. Flux
Ferrites are materials
A. Paramagnetic
B. Diamagnetic
C. Ferromagnetic
D. None of the above
The two conductors of a transmission line carry equal current I in opposite directions. The force on each conductor is________________?
A. Proportional to 7
B. Proportional to x
C. Proportional to distance between the conductors
D. Inversely proportional to i